How can we threshold a signal in both positive and negative sides?

I have a signal with values in both positive and negative sides. I want to threshold in both sides. I have used this code:

threshold=0.5

for i=1:length(signal)

if signal>threshold && -signal>0.5

signal_new(i)=signal

else

signal_new(i)=0

end

end

But I got signal with only positive side. Can anyone help me with thresholding at both sides?

Answer 1

[Star Strider]

I am not certain what you want as the result.

The for loop and if block are not necessary. You can do this with logical indexing. The logical indexing here are:

(signal_new >= threshold)

(signal_new <= -threshold)

Try this —

Fs = 256;
t = linspace(0, 1000, 1001)/Fs;
signal = sin(2*pi*t*2);

threshold = 0.5;
signal_new = signal;
signal_new(signal_new >= threshold) = threshold;
signal_new(signal_new <= -threshold) = -threshold;

figure
plot(t, signal)
hold on
plot(t, signal_new)
hold off
grid
xlabel('Time')
ylabel('Amplitude')
legend('Original','Threshold', 'Location','best')

.